i3c: master: svc: Use readsb helper for reading MDB

The target can send the MDB byte followed by additional data bytes.
The readl on MRDATAB reads one actual byte, but the readsl advances
the destination pointer by 4 bytes. This causes the subsequent payload
to be copied to wrong position in the destination buffer.

Cc: stable@kernel.org
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Stanley Chu <yschu@nuvoton.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250318053606.3087121-3-yschu@nuvoton.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index a72ba5a7edd4b6aa1c48f4744a2424606ceed3da..57b9dec6b5a8909d8d11bcc572bc684e5624a190 100644 (file)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -425,7 +425,7 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
               slot->len < SVC_I3C_FIFO_SIZE) {
                mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
                count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl);
-               readsl(master->regs + SVC_I3C_MRDATAB, buf, count);
+               readsb(master->regs + SVC_I3C_MRDATAB, buf, count);
                slot->len += count;
                buf += count;
        }